Implement per-context filtering

[lttng-tools.git] / src / lib / lttng-ctl / filter / filter-visitor-generate-ir.c

diff --git a/src/lib/lttng-ctl/filter/filter-visitor-generate-ir.c b/src/lib/lttng-ctl/filter/filter-visitor-generate-ir.c
index e1cab3468686691ecae04fbd680bf7bf4f174182..1458cc72857dc2eb4378603d0fe6c180e4108537 100644 (file)
--- a/src/lib/lttng-ctl/filter/filter-visitor-generate-ir.c
+++ b/src/lib/lttng-ctl/filter/filter-visitor-generate-ir.c
@@ -56,6 +56,7 @@ struct ir_op *make_op_root(struct ir_op *child, enum ir_side side)
                return NULL;
        case IR_DATA_NUMERIC:
        case IR_DATA_FIELD_REF:
+       case IR_DATA_GET_CONTEXT_REF:
                /* ok */
                break;
        }
@@ -140,6 +141,26 @@ struct ir_op *make_op_load_field_ref(char *string, enum ir_side side)
        return op;
 }
 
+static
+struct ir_op *make_op_load_get_context_ref(char *string, enum ir_side side)
+{
+       struct ir_op *op;
+
+       op = calloc(sizeof(struct ir_op), 1);
+       if (!op)
+               return NULL;
+       op->op = IR_OP_LOAD;
+       op->data_type = IR_DATA_GET_CONTEXT_REF;
+       op->signedness = IR_SIGN_DYN;
+       op->side = side;
+       op->u.load.u.ref = strdup(string);
+       if (!op->u.load.u.ref) {
+               free(op);
+               return NULL;
+       }
+       return op;
+}
+
 static
 struct ir_op *make_op_unary(enum unary_op_type unary_op_type,
                        const char *op_str, enum ir_op_signedness signedness,
@@ -224,7 +245,8 @@ struct ir_op *make_op_binary_numeric(enum op_type bin_op_type,
        /*
         * The field that is not a field ref will select type.
         */
-       if (left->data_type != IR_DATA_FIELD_REF)
+       if (left->data_type != IR_DATA_FIELD_REF
+                       && left->data_type != IR_DATA_GET_CONTEXT_REF)
                op->data_type = left->data_type;
        else
                op->data_type = right->data_type;
@@ -475,7 +497,8 @@ void filter_free_ir_recursive(struct ir_op *op)
                case IR_DATA_STRING:
                        free(op->u.load.u.string);
                        break;
-               case IR_DATA_FIELD_REF:
+               case IR_DATA_FIELD_REF:         /* fall-through */
+               case IR_DATA_GET_CONTEXT_REF:
                        free(op->u.load.u.ref);
                        break;
                default:
@@ -522,6 +545,40 @@ struct ir_op *make_expression(struct filter_parser_ctx *ctx,
                }
                return make_op_load_field_ref(node->u.expression.u.identifier,
                                        side);
+       case AST_EXP_GLOBAL_IDENTIFIER:
+       {
+               struct filter_node *next;
+
+               if (node->u.expression.pre_op == AST_LINK_UNKNOWN) {
+                       fprintf(stderr, "[error] %s: global identifiers need chained identifier \n", __func__);
+                       return NULL;
+               }
+               /* We currently only support $ctx (context) identifiers */
+               if (strncmp(node->u.expression.u.identifier,
+                               "$ctx", strlen("$ctx")) != 0) {
+                       fprintf(stderr, "[error] %s: \"%s\" global identifier is unknown. Only \"$ctx\" currently implemented.\n", __func__, node->u.expression.u.identifier);
+                       return NULL;
+               }
+               next = node->u.expression.next;
+               if (!next) {
+                       fprintf(stderr, "[error] %s: Expecting a context name, e.g. \'$ctx.name\'.\n", __func__);
+                       return NULL;
+               }
+               if (next->type != NODE_EXPRESSION) {
+                       fprintf(stderr, "[error] %s: Expecting expression.\n", __func__);
+                       return NULL;
+               }
+               if (next->u.expression.type != AST_EXP_IDENTIFIER) {
+                       fprintf(stderr, "[error] %s: Expecting identifier.\n", __func__);
+                       return NULL;
+               }
+               if (next->u.expression.pre_op != AST_LINK_UNKNOWN) {
+                       fprintf(stderr, "[error] %s: dotted and dereferenced identifiers not supported after identifier\n", __func__);
+                       return NULL;
+               }
+               return make_op_load_get_context_ref(next->u.expression.u.identifier,
+                                       side);
+       }
        case AST_EXP_NESTED:
                return generate_ir_recursive(ctx, node->u.expression.u.child,
                                        side);